v0.3.6: the agent sees its desk

HeartBeat 2.0 v0.3.6 lets the agent see its own desk, and makes a role budget you set a real ceiling.

• The agent can read its desk. The pulse tool has a new read-only desk action. At any point in a turn, the agent can check its roles, what's due, whether messages are held, and the turns, messages and cost left today. It's the same view as /pulse desk.

• A role budget you set is a ceiling. After /pulse budget <id> 3/day, the agent can go under 3 but never over it. Only your own /pulse budget command raises it, and a lowering you ask the agent for becomes the new ceiling. Before, the agent could raise it back to the profile maximum outside a wake turn.

• Honest pacing feedback. A cron wake follows its schedule, so the tool now says when it ignores a next_check request. Idle hints offer only what works for that kind of wake: roles can't become watchers, own time is your setting, and the built-in check-in gets no hint.

• README: your first hour. There's now a five-step walkthrough from install to seeing silent work on the desk. The command and settings tables now list roles, the desk, budgets, own time and the daily cost limit.

• Budgets set before 0.3.6: a role budget you set with an earlier version has no record of being yours, so it isn't a ceiling yet. Set it again with /pulse budget <id> <n>/day to make it one.

Upgrade: reinstall and restart the gateway. No settings or database changes. Roadmap: #139.